This application relates to fuel cell systems, and more particularly to fuel cell systems that include a cathode exhaust condenser and a stack cooler.
Because fuel cells offer advantages in efficiency and in emission, interest in utilizing fuel cells as electricity generating plants and/or as a power source for vehicles has been increasing as concerns grow over the supply of fossil-fuel and the environmental effects of conventional fossil-fuel power sources, such as internal combustion engines for vehicles, has been increasing. However, improvements in affordability and compactness may be required before fuel cells become acceptable for wide spread usage, particularly in vehicles.
It is a primary objective of the invention to provide a new and improved fuel cell system.
It is another objective of the invention to provide a fuel cell system that can be made more affordable in comparison to conventional fuel cell systems.
It is another objective of the invention to provide a fuel cell system that can be made more compact in comparison to conventional fuel cell systems.
It is another objective of the invention to provide an improved fuel cell system that can be utilized in vehicular applications.
At least one of more of the above objectives is provided according to the invention in a fuel cell system that includes a fuel cell stack and an integrated heat exchanger unit. The fuel cell stack includes an anode gas inlet to receive a fuel flow, a cathode gas inlet to receive an oxygen flow, a cathode exhaust to discharge cathode exhaust gas, and a coolant passage to direct a coolant through the fuel cell stack.
In one form, the integrated heat exchanger unit includes a cathode exhaust condenser and a fuel cell stack cooler arranged in side-by-side relation to be cooled by a common cooling air stream that flows in parallel through the condenser and cooler. The condenser includes a condensation path in heat exchanger relation with the cooling air stream to reject heat from the cathode exhaust gas to the cooling air stream, a first inlet manifold in fluid communication with the cathode exhaust to receive cathode exhaust gas therefrom and connected to the condensation path to distribute the cathode exhaust gas thereto, and a first outlet manifold connected to the condensation path to receive the cathode exhaust gas therefrom. The fuel cell stack cooler includes a coolant path in heat exchange relation with the cooling air stream to reject heat from the coolant to the cooling air stream, a second inlet manifold in fluid communication with the coolant passage of the fuel cell stack to receive coolant therefrom and connected to the coolant path to distribute coolant thereto, and a second outlet manifold connected to the coolant path to receive the coolant therefrom and in fluid communication with said coolant passage of the fuel cell stack to direct coolant thereto.
In one form, the integrated heat exchanger unit further includes a common fan shroud attached to the condenser and the cooler to direct the cooling air stream from a fan system through the condenser and the cooler.
In one form, the condensation path and the coolant path include a plurality of parallel, spaced heat exchange tubes. The first and second inlet manifolds include a common inlet header tank connected to first ends of the heat exchange tubes, and a first baffle plate liquid tightly sealed in the common inlet header tank to prevent intermixing of the cathode exhaust gas and the coolant. The first and second outlet manifolds include a common outlet header tank connected to second ends of the heat exchange tubes, and a second baffle plate liquid tightly sealed in the common outlet header tank to prevent intermixing of the cathode exhaust gas and the coolant.
In one form, the integrated heat exchanger unit includes a plurality of spaced heat exchange tubes in heat exchange relation with a common cooling air stream, a common inlet header tank connected to first ends of the heat exchange tubes, a first baffle plate liquid tightly sealed in the inlet header tank to divide the inlet header tank into first and second inlet manifolds, a common outlet header tank connected to second ends of the heat exchange tubes, and a second baffle plate liquid tightly sealed in the outlet header tank to divide the outlet header tank into first and second outlet manifolds. The first inlet manifold is in fluid communication with the cathode exhaust to receive cathode exhaust gas therefrom and to distribute the cathode exhaust gas to a first set of the heat exchange tubes. The first outlet manifold receives the cathode exhaust gas from the first set of heat exchange tubes. The second inlet manifold is in fluid communication with the coolant passage of the fuel cell stack to receive coolant therefrom and to distribute the coolant to a second set of the heat exchange tubes. The second outlet manifold is in fluid communication with the coolant passage of fuel cell stack to direct coolant thereto from the second set of heat exchange tubes. The first and second sets of heat exchange tubes are arranged so that the common cooling air stream flows in parallel past the first set of heat exchange tubes and the second sets of heat exchange tubes.
Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings and claims.